GENEVA, Aug. 24 (Xinhua) -- The World Health Organization (WHO) on Sunday said it is working to ensure a WHO-deployed international health worker who has contracted Ebola in Sierra Leone receives the best care possible including the option of medical evacuation to another care facility if necessary.

Since the beginning of the international response to the outbreak in March, WHO has deployed nearly 400 people from across the Organization and from partners in the Global Outbreak Alert and Response Network to help respond to the disease in Guinea, Liberia, Nigeria and Sierra Leone.

According to WHO, the Ebola virus is spread through contact with bodily fluids, people giving care or working around infected patients are known to be a high-risk group.

As of Aug. 20, the total number of cases attributed to Ebola virus disease in Guinea, Liberia, Nigeria, and Sierra Leone has reached 2,615, including 1,427 deaths.

At present, no cases have been confirmed anywhere else in the world outside these four countries.